Steering mechanism for a boat having a planing hull

Abstract

A boat includes a planing hull, a propeller, a main rudder, and a pair of flanking rudders. The planing hull has port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides. The propeller is positioned forward of the transom and beneath the hull bottom. The main rudder is positioned aft of the propeller. The main rudder has a rotation axis about which the main rudder rotates. The flanking rudders are positioned forward of the propeller. One of the flanking rudders is positioned on the port side of the centerline, and the other flanking rudder is positioned on the starboard side of the centerline.

What is claimed is: 
     
       1. A boat comprising:
 a planing hull including a port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides; 
 a propeller positioned forward of the transom and beneath the hull bottom, the propeller having a diameter; 
 a main rudder positioned aft of the propeller, the main rudder having a rotation axis about which the main rudder rotates; 
 a port flanking rudder positioned on the port side of the centerline, the port flanking rudder having a rotation axis about which the port flanking rudder rotates; 
 a port flanking rudder post passing through the hull bottom, one end of the port flanking rudder post connected to the port flanking rudder and configured to rotate the port flanking rudder about the rotation axis of the port flanking rudder, the port flanking rudder post being positioned forward of the propeller and laterally within the diameter of the propeller; 
 a starboard flanking rudder positioned on the starboard side of the centerline, the starboard flanking rudder having a rotation axis about which the starboard flanking rudder rotates; and 
 a starboard flanking rudder post passing through the hull bottom, one end of the starboard flanking rudder post connected to the starboard flanking rudder and configured to rotate the starboard flanking rudder about the rotation axis of the starboard flanking rudder, the starboard flanking rudder post being positioned forward of the propeller and laterally within the diameter of the propeller. 
 
     
     
       2. The boat of  claim 1 , wherein the planing hull includes at least one of lifting strakes, a hard chine, and a deadrise from 0° to 30°. 
     
     
       3. The boat of  claim 1 , further comprising a drive shaft for rotating the propeller, the drive shaft being aligned with the centerline when viewed from above. 
     
     
       4. The boat of  claim 1 , the boat further comprising a main rudder post passing through the hull bottom, one end of the main rudder post connected to the main rudder and configured to rotate the main rudder about the rotation axis of the main rudder, the main rudder post being located aft of the propeller and laterally within the diameter of the propeller. 
     
     
       5. The boat of  claim 4 , wherein the main rudder post is positioned on the centerline when viewed from above. 
     
     
       6. The boat of  claim 1 , wherein the port flanking rudder post is positioned on the port side of the centerline and the starboard flanking rudder post is positioned on the starboard side of the centerline. 
     
     
       7. The boat of  claim 1 , wherein each of the port flanking rudder post and the starboard flanking rudder post are positioned forward of the propeller a distance that is less than or equal to three times the propeller diameter. 
     
     
       8. The boat of  claim 7 , wherein the port flanking rudder post and the starboard flanking rudder post are located the same distance forward of the propeller. 
     
     
       9. The boat of  claim 1 , wherein each of the flanking rudders further has a neutral position and a forward edge that is angled toward the centerline as viewed from above when the flanking rudder is in the neutral position. 
     
     
       10. The boat of  claim 9 , wherein, when viewed from above, the forward edge of the port flanking rudder is angled toward the centerline at a toed-in angle relative to a line that extends parallel to the centerline and intersects the rotation axis of the port flanking rudder, the toed-in angle of the port flanking rudder being from 0° to 10°, and
 wherein, when viewed from above, the forward edge of the starboard flanking rudder angled is toward the centerline at a toed-in angle relative to a line that extends parallel to the centerline and intersects the rotation axis of the starboard flanking rudder, the toed-in angle of the starboard flanking rudder being from 0° to 10°. 
 
     
     
       11. The boat of  claim 1 , wherein each of the flanking rudders further has a neutral position and a forward edge that is angled away from the centerline as viewed from above when the flanking rudder is in the neutral position. 
     
     
       12. The boat of  claim 11 , wherein, when viewed from above, the forward edge of the port flanking rudder is angled away from the centerline at a toed-out angle relative to a line that extends parallel to the centerline and intersects the rotation axis of the port flanking rudder, the toed-in angle of the port flanking rudder being from 0° to 10°, and
 wherein, when viewed from above, the forward edge of the starboard flanking rudder angled is away from the centerline at a toed-out angle relative to a line that extends parallel to the centerline and intersects the rotation axis of the starboard flanking rudder, the toed-in angle of the starboard flanking rudder being from 0° to 10°. 
 
     
     
       13. The boat of  claim 1 , further comprising:
 a main rudder post passing through the hull bottom, one end of the main rudder post connected to the main rudder and configured to rotate the main rudder about the rotation axis of the main rudder; 
 a main tiller arm connected to the other end of the main rudder post and configured to rotate with the main rudder post; 
 a flanking rudder tiller arm connected to an end of one of the port flanking rudder post and the starboard flanking rudder post, the flanking rudder tiller arm configured to rotate with the one of the port flanking rudder post and the starboard flanking rudder post; and 
 a linkage connecting the main tiller arm and the flanking rudder tiller arm, the linkage being connected to the main tiller arm at a first connection point and connected to the flanking rudder tiller arm at a second connection point, wherein the distance between the first connection point and the main rudder post is greater than the distance between the second connection point and the flanking rudder post. 
 
     
     
       14. The boat of  claim 1 , further comprising:
 a port tiller arm connected to an end of the port flanking rudder post and configured to rotate with the port flanking rudder post, the port tiller arm being angled in a direction from the port flanking rudder post away from the centerline when viewed from above; 
 a starboard tiller arm connected to an end of the starboard flanking rudder post and configured to rotate with the starboard flanking rudder post, the starboard tiller arm being angled in a direction from the starboard flanking rudder post away from the centerline when viewed from above; and 
 a linkage connecting the port tiller arm and the starboard tiller arm. 
 
     
     
       15. The boat of  claim 14 , wherein the linkage is connected to the port tiller arm at a first connection point and is connected to the starboard tiller arm at a second connection point, and
 wherein, the distance between the first connection point and the port flanking rudder post is the same as the distance between the second connection point and the starboard flanking rudder post. 
 
     
     
       16. The boat of  claim 14 , wherein the linkage is adjustable. 
     
     
       17. A boat comprising:
 a planing hull including a port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides; 
 a propeller positioned forward of the transom and beneath the hull bottom, the propeller having a diameter; 
 a main rudder positioned aft of the propeller, the main rudder having a rotation axis about which the main rudder rotates; 
 a flanking rudder positioned forward of the propeller and offset from the centerline, the port rudder having a rotation axis about which the flanking rudder rotates; and 
 a flanking rudder post passing through the hull bottom, one end of the port flanking rudder post connected to the flanking rudder and configured to rotate the flanking rudder about the rotation axis of the flanking rudder, the flanking rudder post being positioned forward of the propeller and laterally within the diameter of the propeller. 
 
     
     
       18. The boat of  claim 17 , wherein each of the flanking rudder and the flanking rudder post is positioned on the port side of the centerline. 
     
     
       19. The boat of  claim 17 , wherein each of the flanking rudder and the flanking rudder post is positioned on the starboard side of the centerline. 
     
     
       20. The boat of  claim 17 , wherein the flanking rudder post is positioned forward of the propeller a distance that is less than or equal to three times the propeller diameter.